Optical apparatuses can be utilized to sense parameters such as acceleration, motion and/or pressure, among others. For instance, optical apparatuses can be used to sense seismic energy. The seismic energy can be naturally occurring, or can be imparted by a seismic energy source for the purpose of performing seismic surveys, geophysical exploration, and/or permanent reservoir monitoring.
Sensing seismic energy can include detecting motion on and/or near the Earth's surface. Some optical apparatuses, such as geophones, can produce signals that are related to velocity. Some other optical apparatuses, such as accelerometers, can produce signals related to the time derivative of velocity, i.e., acceleration. Some other optical apparatuses, such as inclinometers, can produce signals related to a relative orientation of the device with respect to the Earth's gravitational pull. These optical apparatuses can generate an output signal in response to a detected physical parameter. The output optical signal can be a change for an input wavelength, a change in phase to a signal, or an interference pattern of the signal resulting in response to changes in the physical parameter.